CVE-2026-123785 Fluxbox through 1.3.7 Infinite Loop via Menu::updateMenu() Style Geometry
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-123785?
CVE-2026-123785 is a medium-severity vulnerability in fluxbox, published on 6 Nov 2026.
Official description
Fluxbox through 1.3.7 contains an infinite loop vulnerability in Menu::updateMenu() in src/FbTk/Menu.cc that allows attackers to hang the window manager via crafted style geometry values. Attackers can supply a style with an oversized unbounded menu.titleHeight so the column loop never terminates, causing sustained CPU use and denial of service at startup.
Weakness: CWE-835
Which versions are affected by CVE-2026-123785?
How do I fix CVE-2026-123785?
No fix has been published for CVE-2026-123785 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-123785 being exploited?
There is no known exploitation of CVE-2026-123785 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-123785, GHSA-8g4r-mwj3-fw99, UBUNTU-CVE-2026-123785.